Muffling device for compressors



y 1937- c. STEENSTRUP 2,080,236

MUFFLING DEVICE FOR COMPRESSORS Filed Nov. 21, 1935 33 Fig.1.

Inventor; Chr'i sbiom Sheen scf'up,

y WQ/I/EZCSAQMLM is Attorney.

Patented May 11, 1937 PATENT OFFICE MUFFLING DEVICE FOR COMPRESSORS Christian Steenstrup, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application November 21, 1935, Serial No. 50,925

5 Claims. (Cl. 230-232) My invention relates to muflling devices for compressors.

Itis an object of my invention to provide a fluid mufliing device for compressors, which requires a minimum number of parts, as well as a minimum alteration in the construction of the compressor in applying the muiiiing device thereto, which is simple and rugged in construction, and which is effective in operation;

Further objects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the accompanying drawing in which Fig. 1 is a side elevation, partly in section, of a refrigerating machine including a refrigerant compressor provided with a mufiling device embodying my invention; Fig. 2 is a fragmentary sectional view along the line 2--2 of a portion of the mufiling device shown in Fig. 1, and

Fig. 3 is a fragmentary sectional view of a portion of a modified form of mufiiing device which may be used on the refrigerant compressor shown in Fig. 1.

Referring to the drawing, I have shown in Fig. 1 a refrigerating machine, designed for household use, which includes a rotary type refrigerant compressor ill provided with a substantially cylindrical outer compressor casing The compressor II] is driven by a vertical electric driving motor l2, the compressor being secured to the lower end of the driving motor. The compressor l0 and driving motor H are supported on a plurality of vertical helical compression springs 13 arranged at spaced intervals about the periphery of the motor l2. The upper ends of the springs it are secured by suitable bolts l5, to integral laterally projecting feet it formed on the motor frame. The lower ends of the springs l3 are tightlyfitted on plugs it which are in turn rigidly secured to the bottom of a cylindrical hermetically sealed steel casing H, which encloses the motor l2 and the compressor Hi.

The compressor it is provided with inlet and exhaust ports it and M, respectively. I have illustrated a device embodying my invention for mufiiing the sound of compressed vaporized refrigerant discharged from the exhaust port W. This device includes outwardly extending annular integral reenforcing webs 2|]! and 2| formed on the compressor body or casing H and extending about the same. The webs and 2t of the compressor.

are arranged on opposite sides of the exhaust port l9 and in spaced relation thereto, A substantially cylindrical sleeve or closure member 22, made of cold-rolled sheet steel or the like, is supported on the webs 20 and 2| and extends about the compressor casing The sleeve 22 thus cooperates with the webs 20 and 2| to form a fluid mufiiing chamber 23 adapted to receive compressed vaporized refrigerant discharged from the exhaust port IS. A series of vertical reenm forcing webs 24 extend between the-webs 20 and 2| and a notch 25 is provided in each of the vertical webs 24 in order that the mufiling chamber 23 communicating with the exhaust port l9 may extend substantially entirely about the compressor casing The adjacent surfaces of the webs 20 and 2| and the sleeve 22 are arranged with relatively narrow portions thereof in alternate contacting and spaced relationship in order to form a plurality of restricted fluid outlet mufiling passages from the chamber 23 to the interior of the casing As illustrated in Figs. 1 and 2, a plurality of relatively narrow parallel notches or slots 26 and 21 are milled or otherwise formed in the edges of the webs 20 and 2|, respectively, and extend transversely thereacross. The sleeve 22 thus cooperates with the notched portions of the webs 20 and 2| to define a plurality of restricted fluid outlet mufiling passages extending from the chamber 23 to the interior of the casing IT.

A body of lubricant Ila is maintained in the bottom of thecasing H, the lubricant being circulated to the moving parts of the compressor II] by a pump Illa which is mounted on the bottom The lower edge of the sleeve 22 is preferably immersed in the body of lubricant l'la. Any lubricant which is entrained by the vaporized refrigerant in the compressor is discharged from the compressor into the chamber 23 and separates by gravity in the chamber 23 from the vaporized refrigerant. The lubricant thus separated from the refrigerant in the chamber 23 drains through the notches 26 formed in the lower web 20 and down the inner surface of the sleeve 22 back into the body of lubricant lla.

In Fig. 3,.I- have illustrated a modified form of sleeve and web construction embodying my invention, and which may be applied to the compressor l0 shown in Fig. 1. A portion of a corrugated sleeve 22a is shown in Fig. 3, which may be substituted for the sleeve 22 shown in Fig. l, and which cooperates with a smooth-edged web 28. The web 22 is similar to the webs 2B and 2|, shown above, vaporized refrigerant, such as methyl;-

formate, is compressed by the compressor Hi and discharged therefrom through the exhaust port I9 into the mufliing chamber 23. Whether the compressor I is of the rotary or reciprocatory type, the compressed vaporized refrigerant is ordinarily discharged therefrom in rapid puffs and, as a consequence, vibrations are set up in the compressed refrigerant of a frequency well above the lower limit of the audible range. The compressed gaseous refrigerant in the chamber 23 passes therefrom through the fluid outlet passages formed by the notches 26 and 21 into the interior of the casing l1. Since the passages formed by the notches 26 and 21 are very restricted in cross section, the vibratory motion of the compressed gaseous refrigerant passing therethrough is minimized. It will be noted that the cubic capacity of the chamber 23 is large as compared with the displacement of the compressor l0 and, consequently, the back pressure on the compressor [0 at the exhaust port l9 thereof is not unduly increased despite the restriction of the passages formed by the notches 26 and 21.

The compressed gaseous refrigerant thus discharged into the casing l'l passes therefrom through a conduit 3| into a, refrigerant circulator passage 32 extending about a cylindrical natural draft air cooled condenser 33 which surrounds the casing IT. The condenser 33 is of the sheet metal type and includes inner and outer sheets of metal 34 and 35 having complementary indentations 36 and 31 formed therein, respectively. The indentations 36 and 31 cooperate to form the refrigerant circulatory passage 32 between the adjacentsurfaces of the sheets 34 and 35. The metal sheets 34 and 35 are rigidly secured together about their edges and between the indentations 3B and 31 formed therein throughout the length of these indentations, preferably by closely spaced spot welds or line welding. The condenser 33 thus formed is supported on a series of radial heat conducting fins 38 which extend between the casing I1 and the condenser 33. The casing I1 is in turn supported on the upper side of a removable top wall 39 of the refrigerator cabinet with which the refrigerating machine is used. Cooling air circulates upwardly over the surfaces of the condenser 33 and between the condenser 33 and the casing l1, due to natural draft, thus dissipating heat from the condenser 33, the casing l1, and the heat. conducting fins 38. The compressed vaporized refrigerant in the refrigerant circulatory passages 32 of the condenser 33is liquefied by the transfer of heat therefrom through the cooling air passing over the surfaces of the condenser 33 and heat conducting fins 38. The refrigerant thus liquefied flows through a conduit 40 to a flow controlling float valve chamber 4| from which it is supplied through a liquid line 42 to a sheet metal flooded type evaporator 43.

The evaporator 43 includes a pair of longitudi nal cylindrical headers 44 and 45 extending along the upper edges thereof. The headers 44 and 45 are connected by a series of U-shaped refrigerant circulatory passages 46 communicating therewith below the normal liquid level therein, and by a pressure equalizing conduit M communicating therewith above the normal liquid level therein. The headers 33 and 45 are maintained about half full of liquid refrigerant and, as a consequence, the refrigerant circulatory passages are maintained flooded with liquid refrigerant. The evaporator 33 is supported on the lower side of the removable cabinet wall 39 within the food storage compartment of the refrigerator which the evaporator is adapted to cool. 'The liquid refrigerant in the evaporator 43 is vaporized by the absorption of heat from the contents of the compartment in which it is located and the refrigerant thus vaporized is collected in the headers 44 and 45 above the level of the liquid refrigerant therein. The vaporized refrigerant collected in the headers is returned therefrom to the compressor I0 through a conduit 48 which communicates with the header 44 above the liquid level therein. The opposite end of the conduit 48 communicates with the inlet port I8 of the compresor l0 through a hollow plug 49 having an inner end 50, which passes through a suitable hole formed in the sleeve 22. The vaporized refrigerant thus returned to the compressor I0 is again compressed and the cycle, above described, is repeated and continued until the temperature of the compartment in which the evaporator 33 is located is lowered to a desired value.

While I have shown a particular embodiment of my invention in connection with a household type refrigerating machine, I do not desire my invention to be limited to the particular construction shown and described and I intend, in the appended claims, to cover all modifications within the spirit and scope of my invention.

' What I claim as new and desire to secure by Letters Patent in the United States is:

1. In combination with a refrigerant compressor comprising a substantially cylindrical casing having an exhaust port in the side wall thereof, outwardly extending webs on the exterior of said compressor casing and extending about the same, said webs being positioned on opposite sides of said exhaust port means including a substantially cylindrical sheet metal sleeve positioned on said webs and cooperating therewith for enclosing the outer end of said exhaust port to form a fluid muflling chamber, the adjacent surfaces of at least one of said webs and said sleeve being arranged with relatively narrow portions thereof in alternate contacting and spaced relationship to form a plurality of restricted fluid outlet muifling passages from said chamber.

' 2. In combination with a refrigerant compressor comprising a substantially cylindrical casing having an exhaust port in the side wall thereof, annular outwardly extending webs on the exterior of said compressor casing and extending about the same, said webs being positioned on opposite sides of said exhaust port, at least one of said webs having a plurality of transverse slots formed in the edge thereof, and means including a substantially cylindrical sheet metal sleeve positioned on said webs and cooperating therewith for enclosing the outer end of said exhaust port to form a fluid mufiling passage, the adjacent portion of said sleeve cooperating with said slots in said one web to form a plurality of restricted fluid outlet mufliing passages from said chamber.

3. In combination with a refrigerant compressor comprising a substantially cylindrical casing having an exhaust port in one wall thereof,

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